An influential British Iron Age king might actually have been a queen, according to new research.

Verica was a ruler of the Atrebates, whose territory covered much of modern-day Hampshire and West Sussex, before they were ousted from power in 40AD and fled to Emperor Claudius in Rome, where they played a central role in the Roman invasion of Britain in AD43.

According to Roman historian Cassius Dio, the invasion of Britain only happened because Verica persuaded Claudius to cross the Channel. Claudius was depicted as “weak-minded and ineffective”, with his policy decisions dictated by women and freed slaves.

Dr Miles Russell, director of archaeological fieldwork at Bournemouth University, who led the research which is included in a new book, Caratacus: Great King Of Britain, said: “Verica is assumed to have been male because of the patriarchal mindset of 19th-century classical historians”.

However, Verica’s name and depiction on a coin from the era as a “slender, feminine, bare-breasted figure riding on horseback” point to them being female.

“Verica was not only critical to the special relationship between Britain and Rome in the early first century AD but was indisputably female,” he added.

Dr Russell said a key clue to Verica’s gender is that the name ends with the letter ‘a’, which was common for female names at the time, such as Cartimandua of the Brigantes (in Yorkshire) and Boudica of the Iceni (in Norfolk).

He added: “People also assume she was a he because of the term ‘rex’ on coins, but rex is a non-gender-specific title; both male and female kings were recognised by Rome, Cleopatra of Egypt being the most famous.

“The use of the Latin title rex on coins shows that Verica ruled with the full authorisation of the emperor.”

Dr Russell said his theory was strengthened by the imagery used on coins from the time and explained: “Whilst other coin-producing British Iron Age leaders portray obviously male warriors, Verica is depicted as a slender, feminine, bare-breasted figure riding on horseback.”

He added: “The story of Claudius committing to something only because a woman told him to fits the trope of this emperor as being submissive and henpecked.

“In effect, Dio was saying that the campaign was undertaken solely because of the whisperings of a barbarian femme fatale.

“Verica’s role was rather more central to the British expedition.

“Having her on board ensured the project was a success, as she provided tactical information and support on the ground.

“The invasion was Claudius’s great triumph – it being the only chance he had to prove he was a successful military leader.

“Verica provided the excuse for regime change and the emperor seized it.”

Dr Russell said that Verica was a major political player of the time whose story had been largely overlooked.

He added: “We should take the archaeological evidence at face value and remember Verica as a female king and one of the earliest and most important of British female leaders.

“Had she not been deposed, fleeing to Claudius for military support, Rome may never have invaded Britain in the first place.”